Annual herbs, 10–90 cm tall. Leaves simple, sessile, opposite, ovate– lanceolate, or lanceolate or linear, 3–10.5 cm long, 0. 5–1.5 cm wide, glabrous on either side, margins coarsely dentate to serrate, acute or acuminate, cuneate at base. Capitula discoid or radiate, on long peduncles, solitary or in lax corymbs. Involucre hemispheric or broader. Phyllaries persistent, 2–seriate, usually distinct, outer phyllaries leafy, green, narrow lanceolate to spathulate, 2–4 cm long much exceeding the florets, inner broadly ovate, 5–10 mm long, membranous. Receptacles flat, paleate, paleae green, sometimes yellow to orange. Ray florets usually 6–8, sometimes 1–seriate, orange–yellow, usually neuter, rarely absent. Disc florets bisexual, fertile, yellow, tube smaller than limb, 4–5 lobed. Staminal filaments glabrous. Style branches lanceolate. Cypselas angular, 5–9.5 mm long, cuneate, margins thickened; pappus of 2– 4 stiff, usually retrorsely barbed awns.